Summary

On 5 December 2011, at about 1030 EDT a Taylorcraft model BC12-D
aircraft, registered VH-PEE, was engaged in taxi trails as part of
a pre-flight inspection for a flight scheduled late in the day. The
pilot reported that, while using a grass runway, 26 km to the
south-east of Gunnedah Aerodrome, NSW the aircraft was struck by a
strong wind gust or Willy-willy and, on attempting to correct with
engine power and right rudder, the aircraft veered off of the
runway. He was unable to regain control and the aircraft
subsequently struck a fence on the northern side of the runway and
flipped over, coming to rest inverted. There were no injuries to
the pilot. The aircraft incurred serious damage which included
damage to the propeller, one wing strut and the wing surfaces.

Past studies have indicated that Willy-willies are unseen,
unpredictable and can adversely affect light aircraft and
helicopters when they are operating on or close to the ground.
Pilots must be vigilant when operating in these areas and be
prepared to react to mitigate the effects of Willy-willies and
maintain control of the aircraft.